Post hole digger



June 14, 1955 c. A. ARI-:Ns

POST HOLE DIGGER 2 Sheets-Sheet l Filed March 9, 1950 June 14, 1955 c.A. ARENS Pos'r HOLE BIGGER` 2 Sheets-Sheet 2 Filed March 9, 1950INVENTOR.

POST HLE DHGGER Charles Anthony Arens, Winamac, lnd.

Application March 9, 1950, Serial No. 148,655

8 Claims. (Cl. 294-50.@

This invention is concerned with an improved post hole digger.

In the digging of relatively narrow deep holes such as for the insertionof posts it has been common practice to use post hole diggers which havegenerally fallen into one of two major classifications. These are theauger type and the clam shell type of post hole diggers.

The auger type of post hole digger is provided with a screw usually ofsheet metal and is advanced into the ground with a twisting motion untila receptacle associated with the screw is filled with earth at whichtime the post hole digger is lifted from the ground and emptied. Theauger type post hole digger is generally satisfactory in soft earth butdoes not satisfactorily bite into hard earth and is stalled completelyby rocks which are frequently encountered in the ground. Additionally,it is rather diflicult to dump the earth from the receptacle when it israised to the surface.

The clam shell type of digger comprises a pair of sharpened shovelblades mounted in close spaced relation on elongated handles pivotallyconnected adjacent the blades. Digging is accomplished by a series ofsuccessive jabs into the ground following which the handles are spreadapart to force the shovel blades together to grip the earth so that itmay be lifted from the hole and readily dumped to one side. This type ofpost hole digger operates satisfactorily in any type of earth and can beaimed to dig around and lift rocks rather than being stalled thereby.

Certain disadvantages are attendant upon the clam shell type of posthole digger. The usual vertical handles rub the hands of the operatorwith a sudden jerking motion each time the digger is jabbed into theearth and causes blisters and callouses. Dirt is often dropped from theblades by failure to keep the handles spread sufiiciently far apart asthey are raised. The most important objection to this type of post holedigger is that the depth of a hole that can be dug relative to its widthis limited. It is apparent that the distance between the handles as theyare spread apart to force the blades together increases from the bottomsto the tops of the handles. As a hole is dug deeper the handles cannotbe spread apart sufficiently far to grip the earth unless the top of thehole is enlarged. Enlarging the top of a hole requires removal ofadditional earth and provides a less firm foundation for a post orrother object set therein.

An object of this invention is the provision of a post hole digger whichis more conveniently manipulated than are those known in the prior art.

A further object of the present invention is the provision of a posthole digger of the clam shell type which is capable of digging holeswhich are deeper relative to their diameter than has heretofore beenpossible.

Yet another object of this invention is the provision of a post holedigger of the clam shell type in which the blades are self locking indirt retaining position.

Other and further objects and advantages of the present invention willbe apparent from the following description when taken in conjunctionwith the accompanying drawings in which:

Figure 1 is a side elevation partially in section of a post hole diggerembodying the elements ofmy invention;

Fig. 2 is a fragmentary side elevation showing certain other parts in adifferent position;

Fig. 3 is a top view of the handle;

Fig. 4 is a sectional view along the line 4 4 of Fig. 3;

Fig. 5 is a perspective view of the top of the handle;

Fig. 6 is a fragmentary perspective view of a portion of the handle;

Fig; 7 is a fragmentary longitudinal view showing the blades andoperating apparatus thereof as taken along the line 7 7 of Fig. 9;

Fig. 8 is a sectional view taken along the line 8 8 of Fig. 7;

Fig. 9 is a cross sectional view taken along the line 9 9 of Fig. l;

Fig. l0 is a perspective view of a part of the shovel operatingmechanism;

Fig. 1l is a perspective view of the top part of the shovel bladecooperable therewith; and

Fig. l2 is a view similar to Fig. 9 of a modified structure.

Generally, my improved post hole digger comprises a pair of opposedshovel blades pivotally mounted adjacent the lower end `of a singleshaft. In the preferred form the blades are maintained in substantialparallelism by spring members which allow the blades to deiiect uponstriking rocks or other impenetrable objects. The shaft comprises a pairof lconcentrically mounted elongated members which are rotatablerelative to one another and transverse handles are Secured to theconcentrically mounted members adjacent the top ends thereof and a camis secured to the bottom end of one such member. The transverse handlesprovide a more convenient hand grip for jabbing the blades into theearth than the vertical handles used heretofore and when moved towardone another rotate the concentrically mounted members relative to oneanother to cam the shovel blades toward one another into earth retainingposition. Apawl and ratchet mechanism is provided to locate the bladesin earth retaining position and this mechanism is readily unlocked byhand when it is desired to dump the earth retained between the blades.It may be seen that the single handle is more readily yelevated, from ahole than the pair of handles heretofore used and that the hole dug neednot be of appreciably greater diameter than the spring between theshovel blades.

Referring to Fig. 1 first, a post hole digger embodying my inventioncomprises a shaft 12 having a pair of opposed shovel blades 14 and 16pivotally mounted adjacent the lower end thereof. The shaft comprisesinner and outer concentric members or pipes 18 and 20 respectively. Atransverse handle 22 is welded or otherwise secured to a collar 24 whichis secured by means such as a nut and bolt 26 to the upper end of theinner pipe 18. A second transverse handle 28 is secured to the outerpipe 20 below the collar 26. The handle 28 comprises a tubular member 30(Fig. 4) welded or otherwise suitably secured to the outer pipe 20. Theunderside of the collar 24 is provided with a ratchet 32 (see also Fig.5) and a pawl 34 secured to a grip member 36 concentrically mounted onthe tubular member 30 is cooperative with this ratchet. A torsion andtension spring 38 is carried within the handle 28 and is anchored at oneend to a cross pin 40 mounted in the tubular member 30. A second crosspin 42 is secured in the grip member 36 adjacent the outer end thereofand provides an anchor for the other end of the spring 38. The tensionand torsion spring 38 normally maintains vthe grip member 36 on thetubular member 30 with the cross pin 42 abutting the outer end of thetubular member 30 with the pawl 34 in engagement with the ratchet 32. Apair of notches 44 are provided in the outer end of the tubular memberso that the grip member may be twisted a quarter revolution to allow thecross pin 42 to seat in the notches 44 and maintain the pawl 34 out ofengagement with the ratchet 32 if it is for any reason desired todisable the automatic locking of the shovel blades.

Referring to Figs. l, 2, 7 and 8, a base plate 46 may be seen to bewelded or otherwise secured to the inner pipe 18 of the shaft 12. Blademounting members 48 each comprising a pair of arms 50, an upstandingflange 52, and top and rear walls 54 and 56 respectively, are pivotallymounted on depending flanges 53 of theibase plate 46 by transverse boltsor pins 60 spaced through apertures in the depending flanges 58 and thearms 50. Each of the blades 14 and 16 has sharpened curved lower edges64 and is provided at its upper edges with anged rear walls 64 (Fig. 11)and side walls or anges 66 substantially perpendicular thereto. Theblades 14 and 16 are identical and may be conventional post hole diggeror shovel blades with the top edges cut to form notches 68 toaccommodate the blade mounting members 48 and with the outer edges bentin to form the flanges 66. The top of each blade 14, 16 interlits with ablade mounting member 48 with the rear wall 64 against the outer surfaceof the wall 56 of the mounting member 48 and with the flanges 66 of eachblade in contact with the inner surfaces of the arms of its mountingmember. The blades may be secured to the mounting members by welding, bya plurality of rivets or nuts and bolts 70 placed through suitableapertures, or by any other desirable means.

The upper corners of the upstanding ange 52 of each mounting member 48are apertured as at 72 and coil springs 74 are anchored in theseapertures and stretch between opposite anges normally to maintain theblades in spaced substantially parallel position as shown in all of thefigures except Fig. 2. A cylindrical cam surface or member 76 is alsoprovided on each upstanding flange 52 and may comprise a length of rodwelded in position.

Referring most particularly to Figs. 7-9, and generally to Figs. 1 and2, a cam 80 may be seen secured by suitable means such as welding, tothe outer pipe 20 adjacent the bottom thereof. This cam bears againstthe camming surfaces or members 76 and is shaped so that when it isrotated counterclockwise as seen in Fig. 9

to bear against these surfaces or members, it will cam readily may begrasped to jab the blades 14 and 16 into the earth 82 as shown in Fig.l. The handle 28 is turned toward the handle 22 as shown in dotted linesin Fig. 3 to force the shovel blades together and this is most easilydone when the handles are not exactly in line at the start. Due to thepawl and ratchet 34 and 32, the han- El,

dles are locked against relative turning away from each other. Theturning of the handle 28 turns the outer pipe 20 of the shaft 12 andwith it the cam 80 to force the blades together to secure a quantity ofearth 34 as shown in Fig. 2. from the earth to dump the quantity ofearth retained. Due to the automatic locking of the blad-es in earthretaining position, little or no care need by exercised to avoidspilling the dirt retained. This is a particularly valuble feature whenworking in a deep hole where the post hole digger is most readilyremoved by a hand over-hand motion on the shaft 12. To dump the earthretained it is only necessary to rotate the grip member 36 against theaction of the spring 38 to free the pawl from the ratchet 32 and turnthe handle 28 away from the handle 22 to the full line position of Fig.3. The

The post hole digger is then lifted springs 74 return the blades totheir initial substantially parallel spaced apart position to allow theearth to be dumped.

A modified structure is shown in Fig. 12 wherein most of the partsincluding the blades 14 and 16, the blade mounting members 4S, the baseplate 46 and shaft 12 may be similar to those described previously.Rather than the cam the outer pipe 20 is provided with a pair or"diametricnlly spaced ears or arms 85. Links 3S are pivotally connectedto these ears and to lugs which replace the cylindrical cam members orsurfaces 76 on the upstanding anges 52 of the blade mounting members 4S.The tension springs 74 are unnecessary as the blades 14 and 16 aremaintained in spaced apart relation by the arms 83. When the handle 28is turned toward the handle 2, the arms push the flanges 52 apart andconsequently the blades 14 and 16 move into contiguous relation toretain a quantity of earth. Dumping of the earth is brought about in thesame manner as in the earlier modification but in this instance theblades are separated positively through the action of the arms 88 ratherthan by spring action.

lt is apparent that l have herein presented an improved post holedigger. The post hole digger is of the clam shell type adapted to dig inany soil of any consistency. The upstanding handle or shaft of the posthole digger is provided with transverse handles which are morecomfortable iu use than the usual vertical handles and the blades arerorced toward one another by turning the transverse handles toward oneanother and are automatice. ly locked in order to remove dirt withoutspilling from a hole of practically any depth relative to its diameter.

Although certain specic embodiments of my invention have been shown, itis to be understood that this is for illustrative purposes only and thatmy invention is to be limited only by the spirit and scope of theappended claims.

1 claim:

l. A post hole digger comprising an elongated shaft including a pair ofrelatively rotatable concentric members, a handle carried by each ofsaid concentric members at corresponding ends thereof, a plurality ofspaced apart opposed shovel blades pivotally supported by the other endor' one of said concentric members, an arm for i. cach of said shovelblades carried by the other concentric member adjacent said shovelblades, and a link interconnecting each arm and shovel blade to pivotsaid shovel blades into contiguous relation in response to relativerotation of said concentric members.

2. A post hole digger comprising an elongated shaft including a pair ofrelatively rotatable concentric members, a pair of elongated handlescarried by said concenric members at corresponding ends thereof and atright angles thereto to rotate said members relatively, a ringlileratchet carried by one of said concentric members adjacent the handlethereon and having ratchet teeth in its face, a pawl carried by handleon the other concentric member for cooperation with said ratchet andreleasable by rotation of the handle about its own axis, a plurality ofspaced apart opposed shovel blades pivotally supported by one of saidconcentric members at the end thereof opposite the handle, and meansinterconnecting said shovel blades and the other concentric mem- 'oer topivot said shovel blades into contiguous relation in response tomovement of said handle means, said pawl and ratchet being spring urgedinto engagement and automatically locking said shovel blades incontiguous relation.

3. A post hole digger as set forth in claim 2 including means fordisabling said pawl and ratchet.

4. A post hole digger comprising a pair of relatively rotatableconcentric shafts, a plurality of spaced apart opposed shovel bladespivotally mounted adjacent their upper edges for pivoting movement aboutaxes lying in a plane substantially perpendicular to said shaftsadjacent the lower end of said shafts, a pair of handles, one

handle connected to the upper end of the inner shaft and the otherhandle connected to the upper end of the outer shaft, said handles beingadapted to be grasped byA the hands to force said blades into the earth,said handles being mounted for relative movement toward one another,said blades being pivotally connected to the lower end of one shaft, andactuating means connected to the lower end of the other shaft to forcethe upper ends of said blades apart on relative rotation of said shaftscausing the lower edges of said blades to come in closer contiguousrelation.

5. A post hole digger comprising a pair of relatively rotatableconcentric shafts, a plurality of spaced apart opposed shovel bladespivotally mounted adjacent their upper edges for pivoting movement aboutaxes lying in a plane substantially perpendicular to said shaftsadjacent the lower end of said shafts, means normally maintaining saidshovel blades in substantial parallelism, a pair of handles, one handleconnected to the upper end of the inner shaft and the other handleconnected to the upper end of the outer shaft, said handles beingadapted to be grasped by the hands to force said blades into the earth,said handles being mounted for relative movement toward one another,said blades being pivotally connected to the lower end of one shaft, andactuating means connected to the lower end of the other shaft to forcethe upper ends of said blades apart on relative rotation of said shaftscausing the lower edges of said blades to come in closer contiguousrelation.

6. A post hole digger as set forth in claim 5 including spring and stopmeans for maintaining said shovel blades in substantial parallelism.

7. A post hole digger comprising a pair of relatively rotatableconcentric shafts, a pair of spaced apart opposed shovel bladespivotally mounted adjacent their upper edges for pivoting movement aboutparallel axes lying in a plane substantially perpendicular to saidshafts adjacent the lower end of said shafts, a pair of handles,

one handle connected to the upper end of the inner shaft and the otherhandle connected to the upper end of the outer shaft, said handles beingadapted to be grasped by the hands to force said blades into the earth,said handles being mounted for relative movement toward one another,said blades being pivotally connected to the lower end of one shaft, andactuating means connected to the lower end of the other shaft to forcethe upper ends of said blades apart on relative rotation of said shaftscausing the lower edges of said blades to come in closer contiguousrelation.

8. A post hole Vdigger comprising a pair of relatively rotatableconcentric shafts, a plurality of spaced apart opposed shovel bladespivotally mounted adjacent their upper edges for pivoting movement aboutaxes lying in a plane substantially perpendicular to said shaftsadjacent the lower end of said shafts, a pair of handles, one handleconnected to the upper end of the inner shaft and the other handleconnected to the upper end of the outer shaft, said handles beingadapted to be grasped by the hands to force said blades into the earth,said handles being mounted for relative movement toward one another,said blades being pivotally connected to the lower end of one shaft, anda cam connected to the lower end of the other shaft to force the upperends of said blades apart on relative rotation of said shafts causingthe lower edges of said blades to come in closer contiguous relation.

References Cited in the le of this patent UNITED STATES PATENTS1,053,730 Jensen Feb. 18, 1913 1,443,138 Littley Jan. 23, 1923 1,553,270Saold Sept. 8, 1925 2,028,680 Mayeda et al. Ian. 21, 1936 2,219,374Spurney Oct. 29, 1940 2,435,473 Sonnenberg Feb. 3, 1948

